Excellent use of this particularly awesome feature of the Venue line. Calculating aortic outflow VTI has always been extremely challenging, but it's ultimately one of the best ways we've found to non-invasively measure cardiac output. There have been a lot of attempts over the last few years to find an adequately accurate surrogate for the VTI so that relatively less-experienced POCUS users could more easily estimate cardiac output with ultrasound (see corrected carotid flow time, etc), but we've never really found one that provided adequate accuracy. This AI-based tool is the way to bring non-invasive cardiac output measurement to the "masses" (of clinicians with less than 1000 cardiac ultrasounds under their belts). In this particular video, Jonny, you seem to use "volume responsive" and "volume tolerant" interchangeably. I've personally always thought of the IVC collapsibility index (when placed in context of the rest of the cardiac POCUS exam) tends to be more a measure of volume tolerance (i.e. would you be harming the patient by giving additional volume), whereas the auto-bolus of the straight leg raise and the measurement of the subsequent change in VTI simulates a real bolus of volume and, since you're looking for increased cardiac output rather than looking for a lack of decompensation and pulmonary edema, is more specifically a test looking for potential volume responsiveness (i.e. would you be helping the patient by giving additional volume). Thoughts on this distinction? Either way, thanks for the vid!
Excellent use of this particularly awesome feature of the Venue line. Calculating aortic outflow VTI has always been extremely challenging, but it's ultimately one of the best ways we've found to non-invasively measure cardiac output. There have been a lot of attempts over the last few years to find an adequately accurate surrogate for the VTI so that relatively less-experienced POCUS users could more easily estimate cardiac output with ultrasound (see corrected carotid flow time, etc), but we've never really found one that provided adequate accuracy. This AI-based tool is the way to bring non-invasive cardiac output measurement to the "masses" (of clinicians with less than 1000 cardiac ultrasounds under their belts).
In this particular video, Jonny, you seem to use "volume responsive" and "volume tolerant" interchangeably. I've personally always thought of the IVC collapsibility index (when placed in context of the rest of the cardiac POCUS exam) tends to be more a measure of volume tolerance (i.e. would you be harming the patient by giving additional volume), whereas the auto-bolus of the straight leg raise and the measurement of the subsequent change in VTI simulates a real bolus of volume and, since you're looking for increased cardiac output rather than looking for a lack of decompensation and pulmonary edema, is more specifically a test looking for potential volume responsiveness (i.e. would you be helping the patient by giving additional volume). Thoughts on this distinction? Either way, thanks for the vid!